Adjustable dental impression tray

ABSTRACT

An adjustable dental impression tray including a primary unit and two complementary movable units slidably mounted telescopically on the primary unit for adjustment with respect thereto. The primary unit is provided with an outwardly extending flexible flap cooperable with a rigid tab and is adapted to receive and secure the movable unit in a predetermined adjusted position with respect to the primary unit.

BACKGROUND OF THE INVENTION

This invention relates generally to new and useful improvements ofdental impression trays, and particularly seeks to provide a noveldental impression tray in which adjustments thereof may readily beeffected.

Adjustable dental trays have been known for many years. U.S. Pat. No.3,890,791 issued June 24, 1975, discloses an adjustable dentalimpression tray including a primary unit and a complementary movableunit slidably mounted telescopically on the primary unit, the primaryunit being provided with a T-slot disposed in registry with acomplementary slot in the movable unit and a threaded securing device.

However, the above patent does not supply the simplicity of constructionand the rigidity, control and locking of the relatively adjustable partsas effected by the inventive construction disclosed herein. The presentinvention is believed to have several advantages over the prior artwhich will become more apparent by referring to the followingdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, isometric view of an adjustable dental impressiontray constructed in accordance with the invention;

FIG. 2 is an enlarged, partly cut-away view of a portion of the dentalimpression tray of the present invention;

FIG. 3 is a top plan view of the movable unit of the dental impressiontray of the present invention;

FIG. 4 is an end view of the movable unit of the adjustable dentalimpression tray of the present invention; and

FIG. 5 is a cross-sectional view taken along section lines 5--5 of FIG.1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, the dental impression tray of the presentinvention can be seen in FIG. 1 to include a primary unit generallyindicated by the numeral 10, and a movable extension unit, generallyindicated by the numeral 16. The primary unit can be seen to include ahandle 14 for grasping by the user and two U-shaped primary legs 11extending outwardly from the handle.

Extending from legs 11 are secondary legs 11a. Secondary legs 11a aregenerally U-shaped as are primary legs 11, but are slightly smaller incross-sectional dimensions. Both legs 11 and 11a have two generallyvertical sidewalls connected by top walls 12 and 12a to form a U-shapedchannel.

Top wall 12a has a tab 11b therein which extends vertically upward fromthe top wall of channel 11a. Furthermore, leg 11a has two slots 11ctherein which permit tab 11b to easily flex upwardly and downwardly.

Extending outwardly from leg 11 over tab 11b is a flexible U-shaped flap13 which has vertical sidewalls 13a thereon. Flap 13 extends outwardlyover tab 11b approximately the same length as the length of leg 11a.

The movable unit 16 is shown in FIG. 1 to have a generally U-shapedcross-section and to have approximately the same length as leg 11a.Movable unit 16 is dimensioned to nest or telescope snugly over leg 11a.Movable unit 16 has a slotted flap 16a having holes or slots 16c thereinand two channels 16b running along the edge of flap 16a. Flap 16a issized to nest comfortably within flap 13, the edges 13a of flap 13 beingreceived within slot 16b of movable unit 16, and tab 11b being receivedwithin slots 16c.

It can thus be seen that when movable unit 16 is aligned with leg 11aand forced thereover, flap 16a fits inside walls 13a of flap 13 andcontacts tab 11b. As movable unit 16 is forced farther onto leg 11a,flap 16a is forced upwardly thereby forcing flap 13 upwardly. Tab 11bcan then engage each one of the slots 16c individually to hold movableunit 16 in any desired position extending outwardly from primary unit10. This position is illustrated in FIG. 5 wherein flap 13 is seen to beforced upwardly by flap 16a, flap 16a being fitted over tab 11b. Flap 13holds flap 16a downwardly on tab 11b.

The dental impression tray of the present invention can be made from anywell known material. Preferably a plastic material such as athermoplastic or thermosetting resin is employed. It can be seen thatthe dental impression tray of the present invention can be easily moldedfrom a plastic composition and will contain only three molded pieces,two of the three molded pieces being identical. Thus manufacture of thedental tray of the present invention is very inexpensive.

It will be understood that although the above-described embodiments ofthe invention are directed to trays for taking full arch dentalimpressions, the principles of the invention are equally adaptable fortrays to be used for taking of quadrant, anterior, edentulus.Furthermore it is to be understood that variations and arrangements inproportions and parts may be made within the scope of the appendedclaims.

What is claimed is:
 1. An adjustable dental impression tray including aprimary impression unit, a movable extension unit telescopically mountedon said primary unit for adjustment relative thereto, and releasablemeans for securing said primary and said extension units in theiradjusted positions, said primary unit being provided with primary legportions having secondary leg portions extending therefrom, said primaryleg portions having first flap means extending outwardly therefrom andover said secondary leg portions, said secondary leg portions having tabmeans cooperable with said first flap means, said first flap means beingmovable relative to said tab means, said movable extension unit beingprovided with second flap means having a series of slot means thereinfor registry with said tab means.
 2. The tray of claim 1 wherein saidprimary leg portions and said secondary leg portions are U-shaped incross-section.
 3. The tray of claim 1 wherein said secondary legportions have slot means adjacent to said tab means to permit said tabmeans to flex upwardly and downwardly.
 4. The tray of claim 1 whereinsaid first flap means and said second flap means flex upwardly anddownwardly.
 5. The tray of claim 1 wherein said tab means are alignedwith said first flap means.
 6. The tray of claim 5 wherein said tabmeans comprises a protuberance extending upwardly from said secondaryleg portions toward said first flap means.
 7. The tray of claim 1wherein said movable extension unit has longitudinal slot means thereinfor receiving sidewall means formed on said first flap means.
 8. Thetray of claim 7 wherein said first flap means and said second flap meansflex upwardly and downwardly.
 9. The tray of claim 8 wherein said tabmeans are aligned with said first flap means.
 10. The tray of claim 9wherein said tab means comprises a protuberance extending upwardly fromsaid secondary leg portions towards said first flap means.